I disagree, fully.
You got guys on the bench- use them. Keep them fresh. Minimize weak spots in players you have.
Yes, in theory, just put 9 guys in the line-up with no weaknesses on D or on splits.
BTW, the 100 win Dodgers started Jason heywood in 98 games vs RHPs and 0 vs LHPs. Looks like a solid platoon, to me. Are they "small market?"